Greening the Local Area Network with Passive Optical LAN

I have been in the world of Wireless Access Points and Mobile for months now, and part of what I started looking at is with 802.11ax coming in 2019-2029 an access point is going to need a 10G connection. Well actually even now there are needs for over 1gigabit connections to access points. The access point I have been playing with for the past week is Xirrus XD2-240 which has a maximum bandwidth of 6.9Gbps. I have two gigabit ethernet connections to the AP which I can set up for failover, aggregate, or load balancing.

An active multimode fiber local area network would be an option to 10gig copper, and scale to higher speeds. Then I found information on passive optical lan (POL). This is the same technology used for FTTH. In researching POL I found information how much greener POL can be. Nokia has this post.

For example, the amount of power consumed by a traditional Ethernet local area network (LAN) is significant. All the active switches and aggregators, not to mention the air conditioning units needed to cool these components, consume a lot of electricity.

A new technology is beginning to gain traction that promises to boost the LAN’s performance and make it much, much greener.

Passive Optical LAN (POL) is to Ethernet LAN what fiber-to-the-home is to copper telephone lines.

POL brings the power of fiber optic broadband technology to enterprises, university campuses, hospitals, hotels or anywhere else that uses a local area network. It is both cheaper and more powerful than Ethernet and, as well as lower energy consumption, holds many other advantages.

Passive technology actively saves 20-40% in energy

CablesThe clue to POL’s energy efficiency is in its name: it is a passive technology. For example, it only needs passive splitters to aggregate data from users and end-points whereas Ethernet relies on active components. Also, POL can be run on a centralized architecture – a rarity in Ethernet LANs larger than a few hundred end-points – and signals can travel up to 30km without needing to be boosted, so there is no need for a server room at the end of every corridor. The performance of a typical POL switch (known as an optical line terminal) is also much greater than an Ethernet switch, so you don’t need as many. In fact, whereas organizations often run separate LANs for different services, POL can handle everything in one. The overall energy savings of POL are therefore substantial.

A comparative study of POL and Ethernet LAN by our Bell Labs Consulting team calculated energy savings of between 20% and 40%, depending on the size and configuration of the LAN. These kinds of figures are invaluable for meeting targets for green initiatives such as LEED certification. And they contribute greatly to POL’s 5-year total cost of ownership being 20%-60% cheaper than active Ethernet solutions.

Cheap and green. Now that’s a good combination. This way to a greener LAN.

I'll write more about POL and other fiber technologies in addition to wireless.